Isaca Updated CISM Exam Questions and Answers by bryson

Performing a bit-by-bit backup of the hard disk using a write-blocking device is the first step to do when a forensic examination of a PC is required, but the PC has been switched off because it helps to create a forensically sound copy of the original evidence without altering or damaging it. A bit-by-bit backup, also known as a physical or raw image, is a complete copy of every bit on the hard disk, including the unallocated or deleted data. A write-blocking device is a hardware or software tool that prevents any write operations to the hard disk, such as updating timestamps or changing file attributes. Performing a bit-by-bit backup of the hard disk using a write-blocking device ensures the integrity and authenticity of the evidence and allows the forensic analysis to be conducted on the duplicate image rather than the original source. Therefore, performing a bit-by-bit backup of the hard disk using a write-blocking device is the correct answer.

After an intrusion has been detected and contained, the system should be recovered to a known and trusted state. The best practice for ensuring the integrity of the recovered system is to install the OS, patches, and application from the original source, such as the vendor’s website or media. This way, any malicious code or backdoors that may have been inserted by the intruder can be eliminated. Restoring the OS, patches, and application from a backup may not guarantee the integrity of the system, as the backup may have been compromised or outdated. Restoring the application and data from a forensic copy may preserve the evidence of the intrusion, but it may also reintroduce the vulnerability or malware that allowed the intrusion in the first place. Removing all signs of the intrusion from the OS and application may not be sufficient or feasible, as the intruder may have made subtle or hidden changes that are difficult to detect or undo.

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ISACA, CISM Review Manual, 16th Edition, 2020, page 2401

ISACA, CISM Review Questions, Answers & Explanations Database - 12 Month Subscription, 2020, question ID 2132

The BEST practice for ensuring the integrity of the recovered system after an intrusion is to restore the OS, patches, and application from a backup. This will ensure that the system is in a known good state, without any potential residual malicious code or changes from the intrusion. Restoring from a backup also enables the organization to revert to a previous configuration that has been tested and known to be secure. This step should be taken prior to conducting a thorough investigation and forensic analysis to determine the cause and extent of the intrusion.

Data backups are recoverable from an offsite location is the most important thing to verify when testing an incident response plan for recovery from a ransomware attack, as it ensures that the organization can restore its data and resume its operations without paying the ransom or losing critical information. Data backups should be performed regularly, stored securely, and tested for integrity and availability. (From CISM Review Manual 15th Edition)

The primary reason for performing a business impact analysis (BIA) is to prioritize critical business processes (B). In CISM, the BIA is a foundational activity for business continuity and resilience planning, designed to identify which business functions are most critical to organizational survival and must be restored first following a disruption. The BIA evaluates the impact of outages over time, enabling management to rank processes based on operational, financial, legal, and reputational consequences.

While establishing recovery point objectives (RPOs) (C) is an important output of the BIA, it is secondary to identifying and prioritizing critical processes. Determining risk mitigation options (A) is part of risk treatment, not the primary purpose of a BIA. Determining information sensitivity (D) relates to data classification, which is a separate governance activity.

CISM guidance clearly positions the BIA as a business-driven exercise that informs recovery priorities, recovery time objectives (RTOs), and continuity strategies. Without first prioritizing critical processes, recovery objectives and continuity planning cannot be effectively aligned with business needs.